Linux下shell的用法

1、read基本讀取

1 #!/bin/bash 2

#testing the read command 3

4echo -n "

enter you name:

" #echo -n 讓使用者直接在後面輸入

5read name #輸入的多個文字將儲存在乙個變數中 6

echo

"hello $name, welcome to my program.

執行：

# ./read.sh

enter you name: wangtao

hello wangtao, welcome to my program.

2、read -p (直接在read命令列指定提示符)

1 #!/bin/bash

2 #testing the read -p option

3 read -p "

please enter your age:

"age

4 days=$[ $age * 365]

5echo

"that makes you over $days days old!

執行：

# ./age.sh

please enter your age:

23that makes you over

8395 days old!

3、read -p （指定多個變數）

1 #!/bin/bash 2

# entering multiple variables 3

4 read -p "

enter your name:

" first last

5echo

"checking data for $last, $first

執行：

# ./read1.sh

enter your name: a b

checking data

for b, a

4、read 命令中不指定變數，那麼read命名將它收到的任何資料都放在特殊環境變數reply中

1 #!/bin/bash  2
# testing the reply environment variable  3
4 read -p "
enter a number: 
"5 factorial=1                         
6for (( count=1; count<= $reply; count++))  7
do8    factorial=$[ $factorial *$count ]   #等號兩端不要有空格  9
done
10echo
"the factorial of $reply is $factorial
"

執行：

./read2.sh

enter a number:

6the factorial of

6 is 720

5、超時, 等待輸入的秒數（read -t）

1 #!/bin/bash 2

# timing the data entry 3

4if read -t 5 -p "

please enter your name:

"name #記得加-p引數，直接在read命令列指定提示符 5

then

6echo

"hello $name, welcome to my script"7

else

8echo

9echo

"sorry, too slow!"10

執行：

# ./read3.sh

please enter your name:

sorry, too slow!

# ./read3.sh

please enter your name: wang

hello wang, welcome to my script

5、read命令對輸入的字元判斷

1 #!/bin/bash  2
# getting just one character of input  3
4 read -n1 -p "
do you want to continue [y/n]? 
"answer  5
case $answer in
6 y | y) echo
7echo
"fine, continue on...";;
8 n | n) echo
9echo
"ok, goodbye"10
exit;; 11
esac

執行：

# ./read4.sh
do you want to continue [y/n]?y
fine, continue on...
./read4.sh
do you want to continue [y/n]?n
ok, goodbye

6、隱藏方式讀取(read -s)

1 #!/bin/bash 2

# hiding input data from the monitor 3

4 read -s -p "

enter your passwd:

"pass #-s 引數使得read讀入的字元隱藏 5

echo

6echo

"is your passwd readlly $pass?

執行：

# ./read5.sh

enter your

passwd

: is your

passwd readlly osfile@206?

7、從文字中讀取

1 #!/bin/bash
2 # reading data from a file
34 count=1
5cat test | while
read line  6
do7echo
"line $count: $line
"8    count=$[ $count + 1]  
9done
10echo
"finished processing the file
"

執行：

./read6.sh

line

1: the quick brown dog jumps over the lazy fox.

line

2: this is a test, this is only a test.

line

3: o romeo, romeo! wherefore art thou romeo?finished processing the

file

摘自：

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